Genomic organization and amplification of the human desmosomal cadherin genes DSC1 and DSC3, encoding desmocollin types 1 and 3

The desmosomal cadherins comprise the desmocollins and desmogleins and are involved in epithelial cell-cell adhesion. There are three desmocollins (DS C 1-3) and three desmogleins (DSG 1-3) that are expressed in a tissue- and development-specific manner. Desmosomal proteins have been implicated in a number of disorders characterized by loss of cell-cell adhesion and trauma- induced skin fragility. Therefore, the desmocollins are potential candidate s for genodermatoses involving epithelial tissues. In order to screen the e ntire DSC1 and DSC3 genes, we have characterized their intron-exon organiza tion. The DSC1 gene comprises 17 exons spanning approximately 33 kb on 18q1 2.1, and the DSC3 gene comprises 17 exons spanning approximately 49 kb on 1 8q12.1. We have also developed a comprehensive PCR-based mutation detection strategy for desmocollins 1, 2, and 3 using primers placed on flanking int rons followed by direct sequencing of the PCR products. (C) 2000 Academic P ress.